The Democratic lawmaker leading an investigation of New Jersey Gov. Chris Christie is not impartial and ought to step aside, Christie ally Rudy Giuliani said Sunday.

In an interview on NBC’s Meet the Press, Giuliani said state Assemblyman John Wisniewski, the head of the special legislative committee investigating the closing of lanes leading to the George Washington Bridge in Fort Lee, N.J., is “no longer an impartial arbiter of the facts” because he had announced that did not believe Christie, “the person who's the ultimate focus of the investigation.”

Former New York Mayor Rudy Giuliani defends N.J. Gov. Chris Christie from remarks made earlier on the show by state Assemblyman John Wisniewski.

Giuliani said Wisniewski “should not be handling this investigation. It gives it no sense of credibility” and is “a partisan witch hunt.”

The former New York mayor said the Democrats have mounted “a very, very well-orchestrated Democratic kind of organizational effort to try to hurt Gov. Christie, who was the only Republican who was beating Hillary Clinton in any poll at any time.”

Christie and Clinton are potential adversaries in the 2016 presidential election.

“The allegations are serious about the closure of the bridge,” Giuliani said. “No question about it. But, on the other hand, the governor faced up to the allegations in a very serious way.”

If the question is one’s fitness to be president, Giuliani said, then Christie is emerging well from the controversy over the George Washington Bridge. “The fact is, things go wrong. Things will go wrong if he or Hillary Clinton become president. Question is how are they going to handle it? He's given a textbook case in how to handle it.”

Appearing on Meet the Press prior to Giuliani, Wisniewski said that allegations by the mayor of Hoboken, N.J. that Christie's lieutenant governor threatened to withhold Super Storm Sandy funds for her city if she didn’t support a development project needed to be investigated. “We don't know if there's more to it,” he said. “But I think it's something the committee has to consider as part of the overall investigation. “

Wisniewski also said the investigation of the actions of officials in the Christie administration was “not preordained” and so far “we have no connection to Governor Christie. We're going to look to see who else in his office knew. We're going to follow the trail where it leads step by step.”

In rebuttal to Giuliani's comments, Wisniewski's spokesman released a statment saying that Giuliani "quite simply has no idea what he's talking about. Chairman Wisniewski has been praised by Republicans for his work and Republicans unanimously voted with Democrats to continue the investigation...."